Parallel Wavelength Converters for Compact Projector Light Source
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Solution Overview
Problem
Existing projector light source apparatuses using a time division color sequential driving method face challenges due to increased size, signal delay from long wires, and decreased display quality caused by varying light source specifications and wiring resistance.
Innovation Solution
A light source apparatus with wavelength converters for blue, green, and red light, where the converters are disposed in parallel and face each other, allowing excitation light to enter via side surfaces and fluorescence to exit for combination, reducing the need for separate wiring and enabling compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light sources are disposed separately to face three surfaces of a dichroic prism, then color separation and combination is achieved, but the apparatus size increases due to required cooler space and wire routing space
Solution Approach 1:
The patent merges the three wavelength converters into a single integrated block where blue, green, and red excitation light enter through adjacent side surfaces and converge to a common exit surface. This combining approach eliminates the need for separate cooler spaces and wire routing paths for each light source, reducing overall apparatus size while maintaining color separation capability through the integrated converter design.
Solution Approach 2:
The patent transitions from a three-dimensional spatial arrangement where light sources face three separate surfaces of a dichroic prism to a planar configuration where three wavelength converters are arranged side-by-side with excitation light entering through side surfaces and converging at a common exit. This dimensional reorganization reduces the required volume by eliminating depth requirements for separate cooler and wire routing spaces.
2Reliability
If separate light source drive circuits are prepared for each color, then light source specifications are satisfied, but device complexity increases
Solution Approach 1:
The patent employs a single light source drive circuit that controls all three light emitting devices (blue LED, green LED, red LED) through time-sequential driving. This universal drive circuit eliminates the need for separate dedicated drive circuits for each color, reducing device complexity while maintaining reliable control of each light source according to its specific requirements through temporal separation of operation.
Solution Approach 2:
The patent uses time-sequential driving where the blue LED, green LED, and red LED are activated in alternating time periods rather than simultaneously. This periodic action allows a single drive circuit to control multiple light sources with different specifications by switching between them in time, reducing circuit complexity while ensuring each light source receives appropriate drive conditions during its active period.
3Ease of operation
If long wires are used to electrically connect separate light sources to drive circuit substrates, then light sources can be positioned separately, but wiring resistance increases causing signal delay and waveform degradation
Solution Approach 1:
The patent merges the electrical connection points by positioning all three light emitting devices adjacent to each other on a single substrate. This combining of positions eliminates the need for long wires extending from separate light source locations to distant drive circuit substrates, reducing wiring resistance and signal delay while maintaining positioning flexibility through the compact integrated arrangement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution results in a compact light source apparatus with reduced wiring resistance, improved image quality, and the ability to use common drive circuits, enhancing the efficiency and cost-effectiveness of the projector.
Implementation Method 1
a first wavelength converter that converts the first excitation light into first fluorescence having a first wavelength band different from a wavelength band of the first excitation light
Data Source
AI summary
A light source apparatus according to an aspect of the present disclosure includes a light source, a first wavelength converter that converts first excitation light into first fluorescence, a second wavelength converter that converts second excitation light into second fluorescence, a third wavelength converter that converts third excitation light into third fluorescence, a light combiner that combines the first fluorescence, the second fluorescence, and the third fluorescence with one another, and a light source driver that causes the light source to output the first excitation light, the second excitation light, and the third excitation light in a time sequential manner. The first, second, and third wavelength converters are disposed in parallel to one another. The excitation light enters the wavelength converters via side surfaces, and the fluorescence exits via end surfaces of the wavelength converters.